Taking the pulse of the Sun during the Holocene by joint analysis of 14C and 10Be

We have studied solar variations during the Holocene (i.e., last similar to 11,700 yr) by combining a new model of the Earth's dipole moment with C-14 data from the IntCal04 record and 10 Be data from the GRIP ice core. Joint spectral analysis of the two nuclide records suggests that the periodic behavior of the Sun was particularly pronounced between 6000-4500 yr BP and 3000-2000 yr BP, with dominating periodicities of similar to 88, similar to 150, similar to 220, and similar to 400 years, while this rhythmic behavior faded during other time intervals. The fact that the two reconstructions, based on radionuclides with distinct geochemical properties, agree with respect to both the frequency and timing of the periodic behavior, strongly suggests that they reflect the actual behavior of the Sun. Subtle but systematic differences between the amplitude spectra may point to an interplay between the climate system and the similar to 220- and similar to 400-year solar cycles during intervals when these were particularly prominent. Citation: Knudsen, M. F., P. Riisager, B. H. Jacobsen, R. Muscheler, I. Snowball, and M.-S. Seidenkrantz (2009), Taking the pulse of the Sun during the Holocene by joint analysis of 14 C and 10 Be, Geophys. Res. Lett., 36, L16701, doi: 10.1029/2009GL039439.